RNA Polymerase structural details

[Rcjohnsen]

Cramer et al. 
(http://www.sciencemag.org/cgi/content/short/292/5523/1863) 
and Gnatt et al. 
(http://www.sciencemag.org/cgi/content/short/292/5523/1876), 
in the 8 Jun 2001 issue, explored the structure of RNA 
polymerase II (Pol II), the enzyme responsible for synthesizing 
messenger RNA off of the DNA sequence.  In particular, in a 
tour-de-force performance, the Gnatt et al. group was able to 
crystallize and map -- at a 3.3-angstrom resolution -- an actively 
transcribing complex of Pol II, DNA, and mRNA, presenting a 
graphic molecular snapshot of gene expression in action.  A 
Perspective by A. Klug 
(http://www.sciencemag.org/cgi/content/short/292/5523/1844) 
provided other insights on this "marvelous machine for making 
messages," and on the importance of the new studies -- which, 
according to Klug, represent "structural biology on a grand 
scale."